In a saucepot, cover potatoes with cold water, bring to boil and cook to tender. Drain and lightly crush potatoes to crack them.
Combine sour cream with chives, lemon juice and zest, EVOO, salt and pepper. Toss potatoes, snap peas, radishes and scallions in dressing.
Heat a cast-iron skillet over medium-high heat. Season the steaks with Kosher salt and coarse black pepper; drizzle with oil.
In a small pot, combine the Tamari, Worcestershire, Dijon, maple syrup or honey and garlic; simmer to infuse garlic flavor.
Cook steaks 5 minutes, turning to brown on both sides then liberally coat steaks with sauce, cook 2-3 minutes more.
Serve steak with potato salad alongside.